Pore‐forming toxins of foodborne pathogens

Abstract

Pore‐forming toxins (PFTs) are water‐soluble molecules that have been identified as the most crucial virulence factors during bacterial pathogenesis. PFTs disrupt the host cell membrane to internalize or to deliver other bacterial or virulence factors for establishing infections. Disruption of the host cell membrane by PFTs can lead to uncontrollable exchanges between the extracellular and the intracellular matrix, thereby disturbing the cellular homeostasis. Recent studies have provided insights into the molecular mechanism of PFTs during pathogenesis. Evidence also suggests the activation of several signal transduction pathways in the host cell on recognition of PFTs. Additionally, numerous distinctive host defense mechanisms as well as membrane repair mechanisms have been reported; however, studies reveal that PFTs aid in host immune evasion of the bacteria through numerous pathways. PFTs have been primarily associated with foodborne pathogens. Infection and death from diseases by consuming contaminated food are a constant threat to public health worldwide, affecting socioeconomic development. Moreover, the emergence of new foodborne pathogens has led to the rise of bacterial antimicrobial resistance affecting the population. Hence, this review focuses on the role of PFTs secreted by foodborne pathogens. The review highlights the molecular mechanism of foodborne bacterial PFTs, assisting bacterial survival from the host immune responses and understanding the downstream mechanism in the activation of various signaling pathways in the host upon PFT recognition. PFT research is a remarkable and an important field for exploring novel and broad applications of antimicrobial compounds as therapeutics.

Bacterial pore-forming toxins

“…Moreover, even for those E. coli strains producing a functional ClyA homologue, the real impact and significance of this toxin in the pathogenicity process is unknown, as these strains produce numerous other toxins and virulence factors [69, 71, 72].…”

“…Furthermore, inactive ClyA variants are present in other enteric pathogens, such as Shigella strains [71], suggesting that ClyA's role in pathogenesis might be limited to a subset of Enterobacteriaceae species. Moreover, even for those E. coli strains producing a functional ClyA homologue, the real impact and significance of this toxin in the pathogenicity process is unknown, as these strains produce numerous other toxins and virulence factors [69,71,72].…”

“…Aerolysin secretion contributes to A. hydrophila -induced sepsis and gastroenteritis [72]. Aerolysin triggers the NACHT- LRR- and PYD domain-containing protein (NALP3) inflammasome [81].…”

Towards Development of Molecularly Imprinted Electrochemical Sensors for Food and Drug Safety: Progress and Trends

“…Compared with natural antibodies, MIPs can be easily modified and controllable in the affinity of receptor sites, which makes it more accessible to recognize different kinds of molecules, no matter small ones or big macromolecules [ 45 , 46 ]. In addition, MIPs show high stability, strong resistance to the environment and biocompatibility, which mean that they are of low cytotoxicity, and can be stored and used in harsh conditions, such as in low or high temperatures, extreme pH solutions, and strong ion strengths [ 47 , 48 ]. Because of their advantages, such as being lightweight, low-cost and easy to use, electrochemical sensors with a high diversity of electroanalytical techniques are expected to be the future generation of analytical systems.…”

“…The ingestion of pathogen and toxin-contaminated food can cause severe illnesses, which pose a huge threat to human health [ 45 , 46 ]. A trace level of pathogen or toxin in the human body could inflict biological damage or even death [ 47 ]. Foodborne pathogens such as Salmonella enterica, Listeria monocytogenes, Escherichia coli, and Staphylococcus aureus, are responsible for poisoning food and water.…”